Voice source characteristics in six premier country singers

Voice source characteristics as derived from inverse filtering were analyzed in 6 country singers' speech and singing. Results showed that the closed quotient varied systematically with vocal loudness, and that glottal compliance (the ratio between transglottal AC volume displacement and subglottal pressure) decreased with increases in fundamental frequency but remained unaffected by vocal loudness. No striking differences were found in source characteristics between speech and singing within subjects. The degree of phonatory press, as judged by a panel of 19 expert listeners, appeared related to the range in which the singer was singing and to the sound pressure level gain from a doubling of subglottal pressure.     

Breathing muscle activity and subglottal pressure dynamics in singing and speech

Previous studies have indicated that the diaphragm may contribute to the accomplishment of the quick and precise subglottal pressure changes required during singing. The present investigation compares data collected from simultaneously recorded electromyograms from breathing muscles and transdiaphragmatic pressure during singing as well as during nonsense and emphatic speech.     

Some Phonatory and Resonatory Characteristics of the Rock, Pop, Soul, and Swedish Dance Band Styles of Singing

This investigation aims at describing voice function of four nonclassical styles of singing, Rock, Pop, Soul, and Swedish Dance Band. A male singer, professionally experienced in performing in these genres, sang representative tunes, both with their original lyrics and on the syllable /pae/. In addition, he sang tones in a triad pattern ranging from the pitch Bb2 to the pitch C4 on the syllable /pae/ in pressed and neutral phonation. An expert panel was successful in classifying the samples, thus suggesting that the samples were representative of the various styles. Subglottal pressure was estimated from oral pressure during the occlusion for the consonant [p]. Flow glottograms were obtained from inverse filtering. The four lowest formant frequencies differed between the styles. The mean of the subglottal pressure and the mean of the normalized amplitude quotient (NAQ), that is, the ratio between the flow pulse amplitude and the product of period and maximum flow declination rate, were plotted against the mean of fundamental frequency. In these graphs, Rock and Swedish Dance Band assumed opposite extreme positions with respect to subglottal pressure and mean phonation frequency, whereas the mean NAQ values differed less between the styles.     

Phonatory control in male singing: A study of the effects of subglottal pressure, fundamental frequency, and mode of phonation on the voice source

This article describes experiments carried out in order to gain a deeper understanding of the mechanisms underlying variation of vocal loudness in singers. Ten singers, two of whom are famous professional opera tenor soloists, phonated at different pitches and different loudnesses. Their voice source characteristics were analyzed by inverse filtering the oral airflow signal. It was found that the main physiological variable underlying loudness variation is subglottal pressure (Ps). The voice source property determining most of the loudness variation is the amplitude of the negative peak of the differentiated flow signal, as predicted by previous research. Increases in this amplitude are achieved by (a) increasing the pulse amplitude of the flow waveform; (b) moving the moment of vocal fold contact earlier in time, closer to the center of the pulse; and (c) skewing the pulses. The last mentioned alternative seems dependent on both Ps and the ratio between the fundamental frequency and the first formant. On the average, the singers doubled Ps when they increased fundamental frequency by one octave, and a doubling of the excess Ps over threshold caused the sound pressure level (SPL) to increase by 8–9 dB for neutral phonation, less if mode of phonation was changed to pressed. A shift of mode of phonation from flow over neutral to pressed was associated with a reduction of the peak glottal permittance i.e., the ratio between peak transglottal airflow to Ps. Flow phonation had the most favorable relationship between Ps and SPL.     

Dependence of jaw opening on pitch and vowel in singers

In singing, F₀ sometimes is much higher than the typical frequency value of F₁. According to previous investigations, sopranos raise F₁ to a frequency near F₀ by widening the jaw opening in such cases. In the present study, the jaw opening was measured in 10 professional singers of different categorizations whose task was to sing an ascending two-octave scale on different vowels. Their normal F₁ values for these vowels were determined at a low F₀. Only for the vowels /a/ and /a/ did the singers widen the jaw opening when F₀ approached the F₁ value measured at a low pitch. For the other vowels, jaw opening was widened, beginning at a higher F₀. It is assumed that for these vowels the singers used other articulatory means to increase F₁.